


Briar Rose Syndrome

by TheBeingOfEverything



Category: Ao no Exorcist | Blue Exorcist
Genre: Aged-Up Character(s), Alternate Universe, Alternate Universe - Fairy Tale, Blood and Gore, M/M, Multi, Other, Sleeping Beauty Elements, Slow Burn, The demon kings are NOT related, Threesome - M/M/M
Language: English
Status: In-Progress
Published: 2019-02-19
Updated: 2019-04-17
Packaged: 2019-10-31 07:00:03
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 19,019
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17844617
Author URL: https://archiveofourown.org/users/TheBeingOfEverything/pseuds/TheBeingOfEverything
Summary: Someone wants to teach Samael some humility. That the form their lesson takes may just kill him is something Rin has an issue with. Roping in a reluctant Amaimon to help him track down the culprit and a cure, Rin begins his quest to wake Mephisto before his sleep becomes permanent.*A Sleeping Beauty AU*Mephisto gets to be the Disney Princess he was always meant to be, Rin is his Prince Phillip, and Amaimon is the talking animal companion.





	1. Wake Me Up (Wake Me Up Inside)

**Author's Note:**

> This idea literally came to me in a dream, so consider this firmly AU to the aoex plot :D 
> 
> Will feature demon kings that haven’t been introduced yet (Beelzebub) or had their personalities fully fleshed out so I’ll have to take some liberties with them :\
> 
> And an… interesting OC I think you guys are gonna like P:
> 
> Song of the Chapter: Muddy Waters by LP  
> https://www.youtube.com/watch?v=Ss8t7a8n0U4

Awareness. 

Where?

It was difficult to put his thoughts in order and consciousness was as tenuous as spider silk.

Sleep tried to pull him under again, lids shuttering as he struggled to focus his bleary vision.

He was floating in a still pool that stretched endlessly around his body until the edges of it faded into a hazy horizon against a formless sky.

The warm waters lapped at his cheek when he tilted his head to stare at gray, almost colorless surroundings with listless eyes.

How had he arrived in this place?

But the memory wouldn’t come to him and the effort it took to recall why that might be important dragged at his mind until it slipped away like so many grains of sand.

Had he always been here?

And…

How would he get out?

He drifted, only the sound of his heartbeat and the faint breath from his lungs echoing in the vast silence keeping him company.

Who was he?

\---

“Hey, Mephisto, you said you wanted to see me after the last mission to check on the Koma Sword?” 

Rin had stepped into the office without knocking, figuring if Mephisto really wanted to keep him out he’d make it apparent pretty quickly.

But…

Rin narrowed his eyes, brows drawing in confusion as all that greeted him was a silent room.

A careful sniff, however, had him instantly wary for some kind of surprise attack. 

Because he could still smell Mephisto somewhere in the room, the demon king’s scent not faded like he’d been there and left, or like the usual scents of someone’s space they regularly occupied but weren’t currently in.

He scanned the room, keeping his back to the door because he would definitely not put it past the absolute bastard of a demon to not be playing a trick on him, waiting for him to drop his guard.

A scrap of familiar white fabric had him zeroing his focus to the side of Mephisto’s desk, hands coming up to defend himself in-case that was the signal Mephisto was waiting for to pounce.

Nothing came at him and Rin let his lips fall back over his fangs, unbending from his tensed crouch to step closer, still not dropping his guard entirely.

As he neared, the scrap of white revealed itself to be the edge of Mephisto’s cape and a shiver of apprehension went down his spine to see it so out of place.

If his cape was there, then where was Mephisto?

Rin made it and peered around the desk, unsure of what he’d find.

“Mephisto!”

He stumbled the rest of the way around, falling to his knees and turning the still body to reveal Mephisto’s face slackened in unconsciousness. 

No, Rin hesitated for all of a second before throwing caution straight to hell and reaching down to prod careful fingers to Mephisto’s jaw, tilting his head to get a better look.

The stillness was not natural at all. Rin wasn’t sure how he knew, but his instincts were screaming that something was horribly wrong with Mephisto.

His heart was pounding for some reason, Rin realized, falling back on his hands from the downed demon and darting his gaze to the rest of the room as if whatever had gotten Mephisto was still there.

A knock came from the door and Rin jerked his head up, realizing the compromising position he’d found himself in and breaking into a cold sweat.

Before he could react, the door opened and an exorcist entered, file held in his hand that he stared down at until he glanced up and noticed Rin.

“Uh,” Rin gulped, still frozen on the floor to the side of the desk beside Mephisto’s body, now more revealed after Rin had moved him so that he was clearly visible from the entrance.

The man stared at him, file held in a limp hand as if unsure how to react.

Rin’s tail twitched in a nervous gesture, breaking the standoff.

He flinched as the exorcist dropped his file and pulled out a phone, mind going blank as he wracked his head for something to say to stop the panicked actions.

“The spawn of Satan has attacked Sir Pheles! I need back-up!” The exorcist barked into the phone, pulling a gun and training it on Rin’s startled form.

“Ah! Wait, no!” Rin scrambled back until his shoulders impacted the wall behind him and he raised his hands to ward off the attack, “I just found him like this! I swear!”

When that only got the gun raised further, aiming for his head now, Rin yelped and threw himself behind the desk, pulling Mephisto along after him and having to use his demonic strength because the bastard was a stupidly tall, dead weight.

“I’m serious! There’s something really wrong with him!” Rin called out, finding he’d hugged Mephisto to his chest in his scrabble for cover, sitting beneath the space under the desk with the demon’s long legs thrown to the side over his lap and his ridiculous white cape a tangled bundle to the other side.

Stomping feet down the hall had Rin cowering over Mephisto and tightening his arms around him in an instinctive move as he darted his panicked gaze around, unable to come up with anything to diffuse the situation.

His nose and ears told him the room had become crowded, more exorcists filing in, each, he imagined, carrying plenty of weapons all aimed at him and every one of them on a hair-pin trigger.

“Step aside!”

Rin ducked further at the shouted command from a new presence, his head now tucked over Mephisto’s shoulder where he froze, heart thudding in his chest and waiting for the exorcists to make their next move.

“Stand down.”

The room quieted, the sound of weapons being shifted reaching Rin’s ears, though his tension failed to ease.

“What’s the situation?”

Rin listened as the first exorcist on the scene explained, fighting to keep from bursting out to correct him when he claimed Rin had felled Mephisto, like that was even possible!

“I see. Exwire Rin Okumura, will you explain yourself?”

Rin felt his breath stutter out of his lungs, relieved that the situation hadn’t devolved into violence. Yet. “I was told to come here after my last mission by Mephisto. When I got here, I found him like this and then that guy came in and called everyone else. I didn’t do anything!”

Silence met his words and Rin’s hands twitched where they’d clenched, white-knuckled, into the suit over Mephisto’s arm and at his back.

“Acceptable, come out, Okumura, we need to find out what happened to Sir Pheles.”

It sounded… too good to be true, that there was someone amongst the exorcists- who he didn’t already know, at least, who wasn’t of the shoot first at the Satan spawn, ask questions later. 

But Rin had no choice at this point. Unless he wanted to jump head-first out of Mephisto’s window behind the desk and plummet to his death. There was always that option.

He settled Mephisto to the ground, trying to be gentle because seeing the usually so animated demon so still had him flat-footed and unsure how to handle him. His hand left the back of Mephisto’s head against the carpet, the long purple bangs hanging limp and looking somehow less vibrant across his face in mussed strands.

Rin forced himself to stand, raising his hands up first over the top of the desk in surrender and hoping they didn’t decide to open fire anyway.

A group of thirteen exorcists stood at the other side of the room by the door, put to order by the man who’d arrived to command them, but Rin could sense the tension vibrating in the air, an angry hornets nest waiting for an excuse to swarm.

“Good.”

And the room became a hive of activity anyway, Rin standing to the side in awkward silence as Mephisto was brought into the open and stretched out until medical and research personal could be brought in, nobody wanting to move him before they could be sure it was safe to do so, since he appeared stable for the moment.

Rin couldn’t seem to take his eyes off Mephisto, the sea of black uniforms moving in and out of his vision becoming a blur around the white figure laying in the center. 

He was startled out of his daze when two people in lab coats entered, walking up to Mephisto as the room fell still to let them closer.

“Who was the one who discovered him like this?” The woman asked, glancing around the room with narrowed eyes.

Rin was indicated, feeling his heart skip a beat at suddenly having the attention back on him as he was called over to where they stood above Mephisto.

“And you say he was already unconscious when you arrived?” The man asked, crouching to study Mephisto closer, shining a light into the demon’s unfocused green eyes.

“Uh,” Rin coughed, voice scratchy, “yeah, uh, I walked in and saw him over behind the desk.”

When that just prompted a low hum from the man, Rin hesitated, but figured he couldn’t get in any more trouble than he already was and blurted out, “um, I don’t know how to describe this, but something feels wrong with him. Really wrong.”

That got a sharp look from the two researchers before they shared another with each other, the woman speaking finally, “and you’re Rin Okumura, spawn of Satan. A demon.”

Er, what? Rin nodded, not sure why that was any more relevant than it had ever been.

“There’s really nothing else I can think of that could fell a demon king, they certainly don’t get sick like we do,” the man muttered, gaze narrowing again as he brought a hand to his chin in thought.

“You’re right, especially if he can sense it,” the woman said, then sighed, and Rin felt anxiety press at his chest. Because that sigh sounded defeated, like over a failed project or a doctor whose patient had just died on the table. 

“It’s the King Killer.”

Rin’s heart dropped into his stomach at the foreboding name and he darted a quick look to the others in the room to see if they knew what it was either, though many seemed as confused as he did. “What’s that, is he gonna be okay?”

The man huffed out a wry laugh, “it’s a curse, also known as Briar Rose Syndrome for the way its effects work. It sends the afflicted into a coma-like sleep until their bodies are consumed by the energy eating away at them. A demon king usually jumps bodies when their host becomes too degraded, but the curse prevents this until they die with their host.”

“It’s happened once before.” 

Rin jerked his eyes up at that. Another demon king? “So you can fix it?”

He flinched when the man shook his head in the negative, “unfortunately there’s never been a cure reported. Actually, the only reason the Order even knows about the fallen king is because the others created records of them, since after their passing all knowledge disappeared from the collective minds of humanity.”

Through the whole explanation Rin couldn’t turn away from the man speaking, the way he so casually implied certain death for Mephisto like it was an unfortunate turn of the weather, and not the terrifying realization it actually was.

“Actually, this is a fascinating opportunity for us,” The woman said, drawing Rin’s horrified attention, blood draining from his face as he watched a keen look form on hers, “we’ve never been able to record the effects of something of this nature and we may never get the chance to again.”

Rin didn’t have any particularly close bond with Mephisto, the elder demon tending to enjoy teasing him every chance he got and generally being an absent caretaker and kind of a frightening, eccentric entity at the best of times. 

But that didn’t mean Rin wanted him to die.

“Then are we to believe Sir Pheles is lost to the Order? Shall I report this to the Grigori so we can get someone to fill his position as head of the Japan Branch?” The exorcist spoke up, staring with a cool gaze down at Mephisto before bringing his attention back to the researchers.

Rin turned frantic, wide eyes on the humans in the room, unable to believe that everyone seemed so calm and business as usual, talking about replacing Mephisto like he was already dead.

“It’s a pity,” the woman responded, shrugging, “I’m sure the Grigori will want to investigate how he was afflicted as this is most certainly an act of aggression against the Order. But at the very least we’ll have another king to study before his body gives out.”

Was that a smile on her face? Was she excited about the situation?

“We should be able to get some interesting results from him that we haven’t had the opportunity to yet, since we needed him alive and couldn’t damage the host body too much before he would have been forced to exit it to find a new one.”

What…

Rin felt a growing fury buzzing in his head, a sickness eating at his insides. His fangs had extended in his mouth without him noticing and he licked his suddenly tapered tongue against them, a surreal stillness taking hold over his body.

“We can start taking samples as soon as the Grigori sign off on it, though I doubt it will be too long since there’s no known cure for this and they won’t want to waste time getting what we can from him.”

The man stood, rubbing a hand at his lab coat idly before waving it at the nearest exorcists, “if you’ll gather the body, we need to transport it to the lower labs. There’s nothing more to do here. Lock up this room and set guards so whatever information regarding the Order inside remains untouched until they send his replacement.”

“Like hell you are.”

The room fell silent at Rin’s dangerous hiss, the two exorcists who’d been lifting Mephisto dropping him back the carpet with a thud as a primal fear from the rising growl coming from Rin registered to their human senses.

“I,” the man stuttered, fumbling the light he’d been about to put away, “I’m sorry?”

Rin’s hands clenched, the claws he’d formed there biting into his palms until blood welled up and dripped to the cream carpet beneath his feet.

“I’m not gonna let you do that to him.”

The man gulped, sweat breaking on his skin and pulse fluttering in his neck when Rin’s gaze slid to meet his, “ah, I’m not sure what you mean? He’s already dead, there’s nothing more to do here.”

The exorcist moved, then, approaching Rin with a wary gait and raising a hand as if to touch his shoulder, “you’d best return to your dorm, Okumura, we’ll have a confidentiality contract- and likely a Morinath Contract done up for you as well about the situation, so be on the lookout for that. Please speak of this to no one in the meantime.”

The hand touched his shoulder.

Rin exploded. 

Screams met his ears as blue flames erupted around him and he shoved the exorcist aside, the man falling with a grunt, to reach Mephisto. He was pulling the demon up into his arms and leaping to his desk, bringing Kurikara up to smash through the window in a swath of flames that preceded him as he followed them to the outside.

Shouts trailed behind him alongside the rain of glass as Rin fell to the roof beneath, tile cracking like a gun-shot when he landed in a ball of blue flames.

He didn’t waste any time, some remainder of his mind knowing it was only a matter of seconds before the shooting started and he had to be out of range.

The rest was focused on not tearing every human in that room apart for the way they’d all went along with what amounted to murder. To torture.

A snarl tore its way from his throat, even though there was no one around to hear him besides Mephisto, having leapt to the next nearest roof to escape from the Academy.

How could-

Those, those disgusting- 

Absolute monsters!

And no one had even said anything!

Rin wanted to spit flames- could feel them flaring from between his fangs anyways, at the cruelty of it all.

Mephisto was a dead weight in his arms as he forced himself to calm, beating back the flames to keep from becoming a beacon for every exorcist in the area since he was sure they’d be alerted soon. 

If they hadn’t been already.

The wind whipped around his body but all he could feel were the faint breaths coming from Mephisto where he held his head to his neck.

He’d made it into the lower levels of the tiered city, hoping the maze of small alleys and mobs of humans would help hide their presence.

Not, Rin grimaced, looking down at the purple hair, pink striped leggings, weird poofy white shorts, and lanky figure of the demon king in his arms, that it would make much difference.

They were too loud, stood out from the crowd- especially since Mephisto was unconscious in his arms and he had a now sheathed sword in his hand.

What could he do?

Rin stared with glazed eyes at the narrow walls of the alley he’d hid themselves in and over the still form of Mephisto, his grip tightening and loosening in his indecision.

Yukio.

Rin snapped his gaze up. Yukio would know what to do.

He cursed the shitty luck that had made him leave his phone with Yukio, though it had been dead anyway. He had to make it back to his dorm somehow, Yukio having parted from him after the mission to shower and get ready for classes the next day.

Path decided, Rin didn’t spend more time thinking about it, very aware of the noose closing in around him with every second wasted.

After strapping Kurikara back into place, he hefted Mephisto more securely in his arms, summoning his energy to begin the trek and hoping he could make it without drawing any more attention.

Rin launched himself between the lower buildings in the city, trying to stay out of view of any main roads and sticking to the narrower passages as much as he could. Especially when he’d caught sight of the familiar black uniforms of the exorcists in the distance.

He needed another way to transport Mephisto, Rin was becoming aware. Because if he needed to fight in a hurry, he’d have to drop Mephisto to get to his sword and that would take too long, leaving him open to attack. 

What he needed was another demon to help him, which, Rin bit at his lip, glancing down to where Mephisto’s hair lashed at his face on the next jump, where was he even gonna be able to find one of those?

Really, the only two demons he regularly associated with, besides Mephisto, were Ukobach and…

“That’s it!” Rin breathed a sigh of relief. 

Kuro. His cait sidhe familiar was the only one who could possibly help him both as another defender and as transport to… wherever he ended up fleeing to. He’d worry about a location later.

That was when a massive force impacted into him and slammed him down to the ground, stealing Mephisto from his arms while he gagged in the crater made by his body.

“What did you do to him.”

It was worded like a question, but it sounded like a threat, Rin vaguely registered, chest heaving in empty breaths as his cracked ribs healed by painful inches.

He coughed once, blood flecking his lips, and he could breathe again, taking in gasps of air into his deprived lungs.

That demon- what was his name again? Who’d attacked him at the amusement park and in the forest was standing across from him, Mephisto leaning against a green-tight clad leg, only held up by a black clawed hand at his collar and head tilted to rest at an uncomfortable looking angle.

“I,” Rin coughed again, voice coming out rough as he pushed himself to unsteady feet, “didn’t do that to him.”

Gold, slit-pupiled eyes narrowed at him as the demon cocked his head, the move making Rin’s hackles raise because it brought to mind striking snakes and the calm before the storm.

“Then who did.” Came the hissed question, once again said as a statement.

“I don’t know!” Rin burst out, feeling his flames roil under his skin as he had to answer the same question for what felt like the millionth time and already prepared to not be believed. “I just found him like that! And they were going to just let him die- they were going to torture him for some stupid experiments or something! I had to get him out of there.”

That got a slight widening of the demon’s eyes, quickly turned down to look at Mephisto before coming back up to meet Rin’s

“Who. Were.”

Rin took a shuddering breath, seeing the demon’s patience running out and knowing he had to talk fast or risk his ire, “the exorcists at the Academy. And the researchers there. They said he was cursed, something called the, er, King Killer? Briar Rose something? I can’t remember but they said it would kill him and there’s no way to cure it.”

The demon blinked at his answer before ignoring Rin to look more closely at Mephisto with curious eyes on his otherwise blank face.

Maybe there was a cure? Rin held his breath as he waited to see if the demon knew more about Mephisto’s condition than the exorcists had, hope fluttering in his chest that he’d be able to leave Mephisto in the other’s hands and forget the crazy last hour of his life.

A fang-filled smirk sliced across the demon’s face.

“Hah!”

Rin’s heart skipped a beat.

“Getting caught in a curse, Samael?” The demon sneered, shaking the limp body in his grip and laughing again, “such a stupid way to go. How the mighty have fallen.”

Rin was on him in a second, fist cracking across his smirking face and knocking him into his own crater at the far end of the alleyway wall.

“You bastard!” Rin snarled at the groaning form from where he kneeled over Mephisto, one clawed hand pressing him to his chest while he held the other in defense over his back.

He was too furious to even be scared by the way the demon rose in silence, any signs of his previous humor wiped from his expression. Only the faint sounds of the city and the slight tap of the blood running down his face to drip to the ground reaching Rin’s ears.

A long, tapered tongue came out to lick one of the red trails, only serving to smear it in a macabre stain on his skin.

The demon leveled a considering look at him and Rin felt a growl start to build when he made to come close again.

Shifting, like boots over gravel, reached Rin’s ears a second before the sound of a cocking gun did and he froze, eyes widening in fear and heart beat stuttering when he realized it was from directly behind him at the entrance to the alley.

“Step away from him, Amaimon, or I’ll start shooting.”

Well, he had a name for the demon, now.

Relief swept through Rin’s chest, gasp leaving his mouth, and he almost turned to the person who’d spoken if not for the instincts telling him to keep his eyes on Amaimon at all times or risk an attack.

Amaimon blinked, a slow move over gold eyes reminiscent of a predator sizing up prey as he watched the newcomer. 

A toothy smile lit on his face and Rin felt his heart drop. “No, you won’t.”

Why wouldn’t he-? Rin turned, then, the need to see what reaction Amaimon’s words had garnered overcoming his instincts.

Yukio stood behind him, arms raised to sight his weapons on Amaimon, expression betraying nothing and aim steady.

Movement came from by his feet and Rin felt another bit of the tension stringing along his spine ease. 

Kuro smiled at him before turning to level a glare at Amaimon with all the fierceness available to his little cat body.

The stalemate continued, Rin caught in the middle, still stuck crouched over Mephisto and watching to see who would break first. He twitched as Yukio tightened his fingers on the twin triggers, waiting for deafening shots to sound, but Yukio was gritting his teeth and lowering his guns a moment later.

“Yukio?” Rin breathed, question in his voice, and he could see Kuro staring in surprise too.

He glanced back to Amaimon and saw him watching with not so subtle triumph on his face.

“He’s right,” Yukio said, not looking happy at all about the admission, “there’s patrols all over the city, I had to sneak into one once I heard the orders go out to the exorcists. I can’t let them know I found you.”

Rin bit at his lip, the sounds from outside the alley suddenly taking an ominous tone to them as if they’d be discovered any second.

“What were you thinking, Rin?” 

Rin flinched at the anger now in Yukio’s voice, knowing it had been coming. “I didn’t have a choice, Yukio, they were gonna just- kill him! Take him apart like some kinda lab experiment, and they wanted me to be quiet about it!”

He was getting angry about it again, snarl forming on his face at the insanity of who were supposed to be the good guys. Though, given what they’d been about to do to him during his own trial, he shouldn’t have been so surprised.

“I couldn’t let them, Yukio,” Rin said, then sighed, staring down at Mephisto as a weariness settled in his bones, “they probably removed that suspension on my execution order, huh.”

It was Yukio’s turn to flinch, dropping his gaze, and answering, “yeah, you’ve got kill on sight orders out for all top-level exorcists and flee and report for all others.”

Up until then, Amaimon had remained quiet, though it was impossible for Rin to forget his presence, and he’d kept him in sight out of the corner of his eye. Not that the blank expression revealed anything of what the demon was making of their conversation or the revealed information anyway.

Still, Rin was immediately paying full attention as Amaimon spoke.

“I’ll help.”

Rin jerked his head up, eyes widening at that declaration and blurting out, “what? Why?”

Amaimon shoved his hands in his pockets, gaze flicking down to Mephisto before he answered, “I owe him. And I’ll be damned twice over if I let a bunch of humans get their hands on him for their worthless experiments.”

“Owe him?”

They didn’t get a chance to talk about it further. 

A shot cracked out, bullet impacting the brick right past Amaimon’s face, the chips shattered and stinging through the air to leave red lines down his cheek as he snarled at the attack.

They’d been discovered.

A group of exorcists had rounded the alley, and Rin could already hear them calling for back-up even as he hunched over Mephisto, trying to make them a smaller target.

Kuro was on them in an instant, breaking their numbers up as he transformed into his larger form to distract them from firing at Rin.

And Yukio was tugging him up, forcing Rin to heave Mephisto into his arms as his twin pulled him towards Amaimon, “I can’t protect you here, Rin, they have me on watch, I barely made it here to tell you. You can’t come home, not without him awake.”

Rin stared, bewildered, at Yukio’s words, just reaching him over the cacophony around them.

He was shoved at Amaimon, Yukio giving the demon a fierce glare, but a pained cry from Kuro had him continuing in a rush, indicating Mephisto with a nod, “he’s the only one who can call them off now. I hate to say this, but it looks like Amaimon is your best bet.”

Yukio had a hand in his hair and was bringing their foreheads together to deliver his final words, quiet, so that only Rin could hear, “be careful, don’t trust him. He’s still a demon.” 

There were plenty of reasons not to trust Amaimon, Rin knew, but, “so am I, Yukio.”

An object was pushed into his hand and Rin took it from Yukio to shove into his pocket, recognizing the feel of a phone as he pulled back.

“This is a burner phone, they can track your cell so I couldn’t get you that.”

Mephisto was grabbed out of Rin’s arms, Amaimon having lost patience. “We don’t have time for this!”

Adrenaline pounded through Rin’s body, seeing Kuro losing ground as more and more exorcists made it to their position.

“Go, Rin, they won’t do anything to me and I need to stay behind to watch the situation from this side, we’ll hold them off until you can get out of here!”

And Yukio was gone, ducking behind the limited cover in the alley and going to help Kuro.

He didn’t have time to say anything else. A hand gripped around his waist and jerked him back and suddenly they were airborne, Amaimon hauling them into the sky above the fighting below. 

Rin had one last look at his twin and his familiar and the black swarm of exorcists converging on them before a snap came and they were gone entirely.

Then it was just Rin, Amaimon, and a comatose Mephisto alone in some random forest meadow where the demon had teleported them in the time it took Rin to blink.

The arm around him let go without preamble and Rin stumbled to the ground, dizzy after the end to the action as he tried to adjust, finding his breaths were coming too fast in his lungs.

Reality had just hit him as what he’d done fell over his head like ice.

He fell to his knees, finding his fingers had claws on them as he dug them into the dirt, shivering and staring at the thin blades of sun-yellowed grass with glassy eyes. “What did I just do?”

“Having regrets already? It’s too late for that,” came the unsympathetic voice from over his shoulder.

For some reason, Amaimon’s callous statement calmed Rin’s panic and he was able to take a steadying breath, leaning back on his feet in a crouch to look up at their surroundings.

Still unfamiliar. 

Rin stood and brushed the dirt from his hands, trying to cover the remainders of the tremors running through them.

“Where are we?”

Amaimon just shrugged, having dropped Mephisto next to his feet in a heap. “Away from the city, we’re safe to talk here.”

Wincing at the uncomfortable position Mephisto had ended up in, Rin had to resist the urge to go adjust him because he would prefer not getting in Amaimon’s personal space any more than he had to.

Now that the adrenaline had worn off, the sense of wrongness that seemed to hover in a miasma from Mephisto’s body had Rin chewing his lip in worry.

“So, you don’t know what’s wrong with him, either?” He forced himself to look back up at Amaimon. “I was hoping another demon would know something about it that they- I mean, the humans, didn’t.”

Amaimon crossed his arms, staring down at Mephisto, mouth tugging into a frown as he studied him. “I recognize the name of the curse. Briar Rose Syndrome.”

Rin felt his heart jolt, though his hopes were crushed at the demon’s next words.

“Samael mentioned it to me. Once. And he refused to talk about it after that time.”

Something about the way Amaimon said it and the way his face closed off had Rin swallowing around a dry throat in uneasiness, not liking the implications.

“Why?”

Those gold eyes watched him and it was like the façade of humanity fell away to reveal an ancient and tired being beneath.

“You mentioned the other name of the curse. King Killer.”

Rin’s breath stopped in his lungs as Amaimon grit his fangs together, head turning down to look at Mephisto with a strange bitterness on his features. “The humans don’t remember, but we used to be nine.”

This was, Rin realized, more insight into demons than he’d ever received in cram classes and he didn’t know what to do with it all.

The look on Amaimon’s face was wiped off as he shook himself out of what Rin thought might be memories. 

“Who was the other?” Rin managed to ask, not knowing if he even wanted to hear the answer but something in him making him anyway, a morbid curiosity bringing the words to his mouth.

Instead of answering, Amaimon glanced up at the sky, shoulders sloping as he shoved his hands back in the pockets of his tattered coat. “Did you know, Space and Time came into being in almost the same instance?”

The non-sequitur threw Rin and he blinked in confusion, “space and time?”

Amaimon cocked a crooked smile at him, “Samael used to be third in the order of power, before Abduxuel was taken by the curse and he moved up a rank by default.”

A touchy subject, then, Rin winced, not knowing how he should feel about the death of a faceless demon king of space. But the information just had his mood worsening and he averted his eyes from the still body on the ground. “So there really isn’t a way to help him. We’re just supposed to watch him fade away?”

“I don’t know.”

That had Rin bringing his eyes back up in shock. “You mean there might be a cure?”

His question got a strange look from Amaimon, an obscure emotion flashing through his eyes as he seemed to consider Rin, though he had no idea why. 

“I wasn’t around for those years when Abduxuel was cursed and died. I only heard about it after it happened.”

“So, someone else might know? One of the other kings?” Rin breathed, hope bringing a smile to his face. “Let’s go, then!”

And was disappointed as Amaimon shook his head in the negative, bringing a clawed thumb up to chew at his long black nail. Rin wanted to press him to explain further but it looked like he was mulling something over and Rin was very aware that any chance of him succeeding in waking Mephisto and getting to go back home now depended solely on Amaimon.

Amaimon sighed, staring skyward and speaking more to himself than Rin, “can’t take you to Lucifer, not with Samael so vulnerable, he wouldn’t be able to resist the weakness. Maybe…”

What?

Rin frowned, “what are you talking about?”

Amaimon let out an irritated mutter, “politics.”

Er, Rin tried to imagine Amaimon involved in human politics and every scenario ended in a pool of blood and screaming people fleeing an angry demon king.

“We’ll go to Beelzebub first,” Amaimon said, nodding to himself at the decision, though the name meant nothing to Rin.

“Who’s Beelzebub?” Rin asked as Amaimon reached to pick Mephisto off the ground, the movement more careful than any Rin had seen him use yet and he wondered why he was being gentle now, though he doubted he’d get an answer.

His question only earned him a disbelieving frown from Amaimon. “You really don’t know anything do you.”

“Hey!” Rin said, scowl forming at the insult. “It’s not my fault everyone thinks I already know stuff about demons, like I didn’t just find out they even existed this summer.”

The long sigh that drew out of Amaimon only made Rin scowl harder, not knowing why he should be any more exasperated by Rin’s lack of knowledge than Rin himself was. 

“And he probably thought it was funny, watching you bump your way around in the dark,” Amaimon grumbled down at Mephisto’s unresponsive face as if cursing the trouble he’d brought them.

Yeah, Rin would definitely say that Mephisto got a kick out of teasing him, not that he didn’t give as good as he got right back, which he was pretty proud of, actually.

Amaimon was already looking impatient so Rin hurried to his side, though he didn’t think he needed to be close to the demon for him to teleport them, he also had no idea how the ability worked. Better safe than left behind.

“So,” he said, hesitant, “where are we going?”

“To get a gift.”

“Huh?”

Amaimon snapped his fingers and they vanished from the meadow.

\---

A ripple disturbed the still waters around him, the first thing that had happened since he’d awoken.

He became even more alert when muffled shouting reached his ears, coming as if from miles away and disturbing him further from the peace he’d settled into.

“…how the mighty have fallen.”

“You bastard!”

His brows twitched.

He felt…

Irritated.


	2. It's In My Nature

**Summary for the Chapter:**

> Rin meets the Lord of the Flies, learns more about demon politics, and realizes the road to finding a cure for Mephisto is going to require a lot more sacrifice than he ever anticipated. From he and Amaimon.

**Notes for the Chapter:**

> Here’s to hoping Beelzebub is revealed to be even slightly like how I’m gonna be writing him or I’ll feel real foolish lololol 
> 
> Also, I don’t understand the demon kings’ teleporting abilities at all? Like Amaimon needs a key to get around Japan but Mephisto and Lucifer can literally just poof and they’re there? 
> 
> Maybe it’s only the strongest kings (Lucifer, Samael, and Azazel, potentially?) that can go where they want, or maybe they have to have a familiarity with the place they’re going to (like that movie Jumper) to be able to teleport there. Or maybe Amaimon can and he’s just using the key to go to specific locations. I’m just giving all the demon kings the ability to teleport wherever they want :\
> 
> (But why can’t Satan then? Since he tried to run away with Yuri but traveled on foot. Idkaaaay~)

Rin opened his eyes from where he’d flinched and closed them, sudden teleportation still not his favorite way to travel.

You never knew what you were going to get when you reached the other side.

“Uh, what?”

Like now, where apparently Amaimon had decided to take them to a rustic looking building in a clearly foreign country- if the language he couldn’t recognize from the people around him was any indication, and the building was also a flower shop.

Or a plant shop? Rin definitely saw green growing things for sale inside someplace he could imagine Shiemi hanging out in, but not the fearsome demon leveling an impatient look his way.

Rin still didn’t understand but followed Amaimon inside for lack of any alternative.

The light chime of the bell over the door and the scents of earth and growing things just added to the surreal nature of the whole experience.

And Rin was blinking over at the utterly bizarre scene of Amaimon interacting with someone in a non-violent way.

Amaimon spoke in that same language he’d been hearing outside, leaving Rin in the dark about what he was asking. Well, supposedly asking, since he couldn’t seem to put effort into not making his questions sound like statements or orders.

But Mephisto was still thrown over Amaimon’s shoulder like a ragdoll and the guy at the front desk had been stunned into silence.

A growl from Amaimon jolted the guy from his daze to stutter out his next words, once again incomprehensible to Rin. Somehow, though, he wasn’t immediately fleeing the scene or calling the local authorities on them and was instead moving further into the shop, gesturing for them to follow.

That was when Rin noticed the pointed ears of the shop-clerk, his hair shifting aside when he went past them, and the situation became a little clearer.

He was forced to watch in silence as they were led around the store to various plants, none of which Rin recognized, but which Amaimon would shake his head at and give a short word that had them on to the next.

They stopped at some kind of cactus-looking thing and Rin crossed his arms, waiting for Amaimon to say ‘no’ to that one too only for the demon to tap a clawed finger against it and nod, saying something that must have been asking for the price.

A poof of smoke later and Amaimon had currency in hand for whatever country they were in and they were leaving, still stunned demon standing by the register as if he couldn’t believe who had just bought a plant from his store.

New plant in tow that Amaimon vanished when they got outside, Rin finally couldn’t contain the questions that had built up through that whole exchange.

“Okay, what? Why did you just buy a cactus?”

Amaimon stared down at him and Rin got the feeling he was wondering at his intelligence levels, familiar with the look after growing up with Yukio. “It’s a carrion flower. It attracts flies but doesn’t kill them.”

“Okay?” Rin repeated, drawing the word out in the hopes that he could get some elaboration out of Amaimon.

Amaimon sighed, tapping a finger to Mephisto’s back, exasperation once again in his voice. “We’re going to Beelzebub, demon king of insects, eighth in Gehenna, and this is a gift for his collection.”

Well, Rin blinked, that was oddly considerate of Amaimon and he said so, only for him let out a huff of amusement.

“It’s politics,” Amaimon said, shaking his head, though Rin had no idea why buying a plant was a part of demon politics.

Still, “uh, shouldn’t we get out of the streets? I think people are starting to stare.”

Amaimon shrugged, clearly not worried about what a bunch of inconsequential humans thought and raised his hand to snap them to their next location.

Once again, Rin found himself staring in wordless awe.

And in another country.

Rolling hills, neat rows of silvery-green trees covering them, and what parts weren’t were covered in sprawling vineyards. Above it all rose a palatial Mediterranean villa with an equally as large glass conservatory next to it.

“Woah!” Rin yelped out, turning to take it all in and wondering how far the land around them belonged to the demon king who owned the place, seeing as there weren’t any other signs of humanity.

Amaimon snorted at his enthusiasm and Rin glared over at him. “Hey, this is the first time I’ve been outside of Japan, I’m allowed to be excited, dammit.”

That got a wry smile out of the demon, a fang flashing beneath quirked lips as he hefted Mephisto more securely over his shoulder and turned to walk up the long driveway to the villa.

“Then this should be eye opening for you.”

Well, he wasn’t wrong, Rin thought as they made it to the villa, though instead of stopping there, Amaimon continued on to the conservatory instead.

They entered a humid greenhouse filled to bursting and Rin’s nose was assaulted by more scents than he could place, overwhelming him until he had to sneeze.

He walked into Amaimon’s back, startling with another yelp and stumbling away a few feet.

“Hey! What gives?”

An unfamiliar presence registered itself to Rin’s senses and he quieted, peering around Amaimon’s shoulder to see the new person. Or rather, the new demon.

Dark features, an olive complexion, and piercing amber slit-pupiled eyes under black curls of hair stood out immediately to Rin. The muddy overalls and dirt-stained gardening gloves registered next. Finally, the demon king’s low voice when he spoke, was, on the surface, calming and with an accent Rin couldn’t place, until the undercurrent of danger- of threat, sent a shiver down Rin’s spine.

“Amaimon,” his gaze flicked to Rin’s before focusing back, “this is a surprise, it’s been awhile.”

Amaimon snapped, bringing the cactus back out, “it has, Beelzebub. I brought a gift.”

Beelzebub, right, Rin grimaced inwardly, wondering why every demon king had to choose such a mouthful of a name because it was really hard to keep them straight in his head.

Beelzebub’s attention was drawn to the plant and Rin saw the flash of interest on his face until he reached to take it, delighted smile forming, “a starfish flower, and a variety I don’t have yet! Thank you, Amaimon.”

“I noticed it on my travels,” Amaimon said, shrugging off the thanks, the motion shifting Mephisto.

“Come, I have to put this in its place,” Beelzebub said, leading them further into the maze of walkways, speaking as he did, “and you can explain to me why you’re here- and why you have Samael and Rin Okumura with you.”

Rin flinched, eyes jerking up to stare at the mention of his name, how?

But Amaimon wasn’t freaking out so Rin forced himself to keep his panic on the inside until he didn’t feel so out of his element.

He became aware, then, of a low buzzing hum permeating the air of the greenhouse and Rin squinted until the source of the noise jumped out at him and he gave a silent gasp.

The whole place was alive with insects. A million crawling, flying, hopping creatures swarming in and out of the foliage and around Rin’s head where he had it tilted back to track the black cloud in the air. Were those flies? Gnats? Mosquitoes? Rin grimaced, really hoping they weren’t that last one.

Understanding reached him about why Amaimon had chosen that particular gift for Beelzebub as he watched a butterfly alight on a nearby flower.

A massive red plant-looking thing grabbed Rin’s attention away from the butterfly, the smell from it hit Rin right after and he fought a gag at the sickly-sweet scent like rot. Flies buzzed through the air in a random pattern in and out of its insides and Rin hurried past it after the demons before he accidentally swallowed one of them or something.

They’d entered a smaller domed section of the greenhouse before they finally stopped. Rin shifted around when neither king said anything, Beelzebub setting the potted plant next to some similar ones and vanishing his gloves away while Amaimon stood back and waited.

“Samael is cursed.”

Rin’s heart jolted at the sudden words from Beelzebub, his back still turned to them as he contemplated the plant.

“Yes, the Briar Rose Syndrome,” Amaimon responded and Rin saw him run a clawed thumb over Mephisto’s back once before stopping when Beelzebub turned around.

“King Killer,” Beelzebub murmured, amber eyes solemn in his face. “This will change everything.”

Rin froze as those eyes were turned on him, not expecting the attention.

“And you? I have to admit, this isn’t how I imagined our first meeting to happen. How do you play into things?”

Hesitation at being addressed had him glancing at Amaimon, only to see him arching a brow, giving him the freedom to talk.

“Ah, I found him like this in his office today and-“

He paused, licking at his dry lips and wondering why it was so hard to talk to this particular demon when for all intents and purposes he appeared the least antagonistic of the kings he’d met so far.

“-The exorcists were just gonna use him like research material without even trying to save him.” He bit the words out, that sharp anger he’d felt earlier turned into bitterness. “They were already writing him off and talking about calling in a new director like he wasn’t still alive.”

Rin knew, after Amaimon’s reaction, the chances were pretty slim that Beelzebub would understand his reasoning any better, but he didn’t know how else to explain himself to them

“I couldn’t let them do that to him, it’s just- wrong.” Rin glanced down at Mephisto when he finished speaking, chewing at the inside of his cheek because he knew he sounded childish to the two demon kings. “So, I grabbed him and ran. And then Amaimon found me.”

Beelzebub gave a slow blink at his words before turning to address Amaimon. “He’s so very… human. I didn’t anticipate that.”

Amaimon sighed, propping a hand on his hip and Rin twitched in irritation. “It took forever and a half just to get him to play with me.”

“Play?” Rin sputtered at the demon’s blasé expression. “You interrupted me in the middle of a mission and stole my sword! And then you almost got me executed by the order!”

“Fascinating.” Beelzebub stared, eyes wide at Rin’s outburst and hand coming up to his chin as he observed him like he was one of his plants.

Before Rin could do anything other than glare at Beelzebub, he was focusing back on Amaimon and Rin let out a silent huff as he shelved his irritation for the moment. He had a feeling that scenarios like this one were going to become fairly regular if he kept up his current trend.

“Then you came to me. Why?”

“I need more information,” Amaimon began, getting down to business. “I wasn’t there for Abduxuel’s cursing or his death and I know you were.”

Rin realized he’d never seen such a side to the demon. In the few interactions they’d had, Amaimon had been impulsive, mocking, and eager for a fight. It was strange, Rin decided, but he wasn’t able to consider it more as Beelzebub spoke again.

“I never expected you to get so involved, Amaimon.” Amaimon shrugged again, wordless, and Beelzebub dropped it, sensing a closed subject when he saw one.

“This is a dangerous path you’re taking.” He hedged along a different route, but, at Amaimon’s stubbornly impassive face, yielded. “Okay, I’ll tell you what I remember from that time, although I wasn’t there the last week of his life.”

“Why not?” Rin asked when it seemed like Amaimon was going to ignore that information.

His question got him a wry smile from the demon king and Rin fought a blush that wanted to rise to his cheeks. Was that considered nosy? Was the answer obvious?

“It… wasn’t a good time to be around Samael, then, his cruelty became-” Beelzebub’s gaze darted away at some memory, “-exaggerated.”

“Whose territory was he brought to?” Amaimon interrupted and Rin wondered why that was important but was starting to suspect it had more to do with ‘politics’ as Amaimon had said earlier.

“This was before their conflict, so Abduxuel was brought to Lucifer’s.”

Lucifer. Rin hid a shiver as he remembered the one encounter he’d had with the demon king of light, his presence and power impossible to forget.

“Why not Samael’s?” Amaimon asked pointedly, fishing for something, if his narrowed eyes and slight frown were anything to go on, though Rin couldn’t guess what.

“That, I’m not sure,” Beelzebub hummed, hand coming to his chin again as he mulled something over, “it seemed to me, at the time, that Samael thought Lucifer would know of a cure, though that was the first time any of us had seen the curse so I couldn’t say why.”

“And the only one he would have told is Lucifer,” Amaimon sighed again, though this time he didn’t hide the frustration or the glare he sent towards Mephisto.

“Yes, a catch-22, as the humans say,” Beelzebub said, sharing in the commiserating, though Rin still wasn’t quite sure what the problem was. Or what a catch-22 was, actually.

Knowing he was going to regret asking, Rin blurted out his question anyway. It was either that or he keep listening to the conversation full of names and terms and other random things he didn’t understand.

“So, if Lucifer is the only one who might know anything, why don’t we just go to him? Er-“

They’d turned stunned eyes on him, and Rin hurried to get the rest out before they inevitably shot him down, “-I mean, not that I want to, but it sounds like he’s the only one who has all the information, right? Unless there’s someone else?”

Beelzebub broke the silence with an inelegant snort, eyes widened in gleeful disbelief until he dissolved into laughter.

“Dammit, I’m serious!” Rin growled out, hands clenching as a flush rose to his cheeks when that just made the demon king laugh harder.

He shot another glare over at Amaimon, finding him watching with an amused smile on his face.

“Ah, to be so young,” Beelzebub said, grinning as he wiped at his eye with a clawed finger. “Samael is defenseless now, with an almost certain death fast approaching, and you are a valuable piece in their war.

He waved a hand, brushing aside Rin’s affronted glower at being referred to as a piece in a war.

“All bets are off now and it’s anyone’s guess as to whether Lucifer will honor the previous terms they set down-”

The grin on Beelzebub’s face widened into something dangerous and Rin felt his breath catch in his lungs at the next words.

“-Or whether he’ll hand you straight over to Father.”

Amaimon drew him away from the sly expression he hadn’t been able to escape on his own, breaking the spell Rin had been trapped in with a cocky remark, “it’s a good thing you ran into me first, the others are caught up in this war and you’re almost as defenseless as Samael.”

Rin wanted to point out that it was Amaimon who ran into him, actually, but Beelzebub was talking again so Rin restrained himself.

“Yes, it’s just become clear to me why you came here, Amaimon,” Beelzebub said, hands on his hips and smiling over at Amaimon. “You needed another neutral party to ease him into our world, it’s surprisingly considerate of you, have you been spending too much time with the humans lately?”

Amaimon sneered at the taunt, “hardly, I needed him to get a crash course or we’d both be dead within days of reaching Gehenna.”

Through it all, Rin grew more and more incensed, tail lashing behind him and his fingers digging claws into his arms where he had them crossed until he snapped out, “fine, I get it, I’m really far behind when it comes to knowing anything about anything. Whatever. Can we get back to fixing Mephisto?”

“He’s optimistic,” Beelzebub muttered to Amaimon.

Then the rest of Amaimon’s words registered with Rin and he froze. “Wait, Gehenna?”

That stopped them from their banter, mood sobering and Rin found himself pinned with two pairs of unnerving eyes. The silence didn’t help with his pounding heart because he hadn’t known what to expect when he’d agreed to Amaimon’s help but going to Gehenna hadn’t been on the list.

His mind flashed to the day everything started, finding out whose son he was, blue flames, Shiro’s death.

And Satan.

He’d almost gone to Gehenna that night through the gate and had avoided thinking about it since.

Rin couldn’t take his eyes off of Amaimon, hoping he’d heard him wrong and knowing he hadn’t.

“As I said, you’ve chosen a dangerous route.” Beelzebub finally responded, before shaking his head and focusing on Amaimon again while Rin recovered, or tried to.

“Then your path is clear. You need to find Astaroth. He would know more than I do, and it may allow you to avoid Gehenna entirely. I hear he’s gotten another body and has been skulking around Assiah for Father and Lucifer.”

Something about the name Astaroth sounded familiar to Rin, though he couldn’t place it, not understanding why it filled him with a low flame of anger and had his fangs itching to drop in his mouth. He sucked at his teeth, trying to calm himself from the weird reaction and listen so he didn’t miss anything else important like possibly going to Gehenna.

But Beelzebub’s last comment seemed to be the signal that they were finished with the visit.

“Let me walk you out,” Beelzebub said, smile back on his face to replace the somber atmosphere.

It was strange, Rin thought, walking behind the two demon kings through the greenhouse. The juxtaposition between the friendly way Beelzebub had been throughout the conversation and the flashes of the demon that he really was meant Rin hadn’t been able to relax the entire time.

At least with Amaimon it was pretty clear he was all demon, no hiding what he was behind a façade of humanity. Mephisto too, in his own mocking way, never pretended to be anything but what he was. Rin was beginning to appreciate that honesty the more demons he met.

There was something incredibly off-putting about Beelzebub that he couldn’t wrap his head around and he wondered if it was just him or there was another reason for it. He would ask Amaimon later, once they were out of the greenhouse. He’d probably get laughed at again, but Rin was finding he didn’t have much in the way of pride holding him back anymore.

His instincts were the only things familiar to him at this point and the rules he’d lived under his whole life weren’t applying to his current situation. So, he was going to ask Amaimon a million questions until the demon got tired of him and told him to shut up because he needed to learn this new world as quick as possible or end up dead.

He didn’t have the luxury to mess around like he had been at the Academy.

And, Rin watched the way Mephisto shifted in Amaimon’s hold, he had an eccentric demon king’s life riding on his not screwing up. It wasn’t just his own life at stake.

“Ah, here, please take some of this for your journey,” Beelzebub snapped his fingers and summoned a large jar of what looked like honey, “the hives are producing and I have more than I ever know what to do with, yet again.”

Amaimon’s eyes lit up as he saw the offering, taking it and vanishing it away to wherever things went when the demon kings did that.

“Thank you, Beelzebub,” the earth king said, grinning at his acquisition, much politer than Rin had ever witnessed from him, though, he was now realizing he knew next to nothing about Amaimon.

And they were outside, Beelzebub saying his farewell to them before returning to the greenhouse. Before Rin could say anything, Amaimon snapped his fingers and warped them away.

Rin gasped at the abrupt teleporting, hand at his chest and turning bewildered eyes up at Amaimon. “Why’d we leave so fast?”

“Can you control your fire enough to burn anything that isn’t your clothes and hair off of yourself?”

“What?” Rin gaped at the weird question.

A rumble caught him even more off-guard and Rin yelped as Amaimon drew his hand up, earth following like a mudslide over his and Mephisto’s bodies until they were completely covered, only to slide away a moment later, leaving them spotless.

“What the hell was that?” Rin asked again, because, what?

Amaimon dropped Mephisto to the ground at his feet and Rin winced, back-peddling when the earth king stalked into his personal space and yanked his shirt collar aside.

“Ah- Hey! What gives?” Rin tried to step away but found his shoulder gripped in Amaimon’s clawed hand while the other scrapped over his skin, sending shivers at having the dangerous black nails so near the artery there.

He felt a sharp pinch and yelped again. “Seriously, what are you doing, dammit?”

And froze when Amaimon brought his hand away to show a large tick that he’d plucked from Rin’s neck.

“Oh my god, why was that in my skin?” Rin asked, shuddering in disgust.

The insect was crushed between black claws and Rin immediately started patting himself down, yanking his jacket off and loosening his tie to search for any more insects that might have hitched a ride.

Was he itching because one of them was burrowing into his skin or was that just a stray hair?

Ew ew ew ewewew!

“Beelzebub wouldn’t let an opportunity like that slip by without at least trying to keep some of his spies on us,” Amaimon finally answered, watching Rin strip to his boxers with impassive gold eyes.

Rin stopped his frantic search, the answer to his question from earlier becoming apparent.

He jerked his gaze up to Amaimon’s, wanting to clarify the suspicion anyway. “I was gonna ask you, he seemed so nice, but I kept feeling like there was something really dangerous about him and I couldn’t relax the whole time we were there. What’s up with him?”

Amaimon nodded, moving back over to wait by Mephisto. “He’s like his insects, he can’t resist stinging his venom into the unsuspecting, it’s in his nature. Your instincts were right to be cautious around him.”

Rin was checking through the fur on the end of his tail and wincing at the pain the tugs at the knots there sent through him when Amaimon crossed his arms, staring at him in confusion.

“Why aren’t you using your flames to burn the insects away?”

“Er,” Rin blushed, hands leaving his tail as it wagged in embarrassment behind him- and was Amaimon tracking it with his eyes? He looked like he wanted to pounce on it. Maybe he was like a cat and movement attracted him?

Rin tucked his tail closer to his leg, forcing it still to avoid it getting attacked or whatever was making Amaimon pay so much attention to it. “Sorry, I panicked.”

He flared his fire and burned whatever insects were there away, moving to pull his clothes back on and pretend he hadn’t just acted like Shima about some bugs in front of the ancient demon king his entire quest depended on.

One last burst of flames took care of whatever insects might have been hiding in his clothes and Rin tugged his shirt down, looking to Amaimon to tell him he was ready to go.

Only to see Amaimon still focused on his tail. “Uh, is there something wrong with my tail? Are there still bugs there? I thought I got them all.”

That snapped Amaimon out of whatever daze he was in, the demon shaking his head and glaring at Rin, though he had no idea what for.

“Put your tail away, it's embarrassing to see it out like that,” Amaimon ordered, brows scrunching as if Rin had done something he couldn’t understand again.

Embarrassing? Rin glanced down at where his tail flicked once against the grass by his feet. “I’ve always kept it out like this and Mephisto never said anything, just that it was a demon’s weakness or whatever.”

The glare Amaimon shot at Mephisto was withering and Rin was glad it wasn’t turned on him, though he still didn’t know why it was a big deal to let his tail out, especially when there weren’t humans around to see it like when he was in class.

“Once again, he’s left me to clean up his mess because he was too busy having a laugh,” Amaimon grumbled at the unresponsive form, indignant

“Does this have something to do with demon etiquette?” Rin hesitated but asked anyway, figuring it might be one of those things he’d need to know if he was going to be going to Gehenna. “Mephisto told me some stuff about that but then he let you out to fight me and, I mean, I know about the heart thing and protecting mine now, but not much else.”

Amaimon actually pinched the bridge of his nose between his claws, eyes closing at Rin’s question. “Yes, and it’s a wonder he taught you at least that much.”

“So, why can’t I keep my tail out?” Rin prodded, though it was nice to get some real answers and not the teasing half-answers he usually got out of Mephisto.

That got a flash of gold directed his way, Amaimon stilling where he’d been rubbing at his face in irritation. A quick calculation seemed to be going on behind those eyes and Rin wondered what that meant for him.

Especially when Amaimon began to smile, a slow widening of his lips to reveal fangs in a sly look as he left Mephisto’s side to make his way towards Rin.

“There’s one reason not to keep your tail out in the open,” he said, voice hinting at something Rin couldn’t guess at, though it reminded him of the tone Mephisto liked to use when talking to him and made Rin shift in nervousness.

“That’s the one I think I made clear when I used it against you in the forest.” Amaimon grinned down at him when he came to a stop a foot away.

“Yeah, Mephisto made that pretty clear too,” Rin muttered, shooting his own glare at Mephisto for the remembered way he’d yanked on his tail in the pocket dimension of Gehenna he’d transferred Rin’s mind to when he’d revealed his true name and nature.

“The other reason is one I’m surprised you haven’t discovered for yourself yet.”

And he squeaked as Amaimon reached down to capture his tail in his hand, dragging along it in a firm movement that sent a toe-curling wave of sensation straight through the length of it and into Rin’s stomach.

“What the _fu_ -uh~“ Rin moaned and dropped his head onto Amaimon’s chest, eyes glazing and hips jolting forward at the heat coiling in him until he realized what, exactly was happening and yelped, jerking away from the demon feeling him up.

He forgot Amaimon’s hand was still attached to his tail and shrieked at the pain when he fell and the hold turned excruciating before Amaimon released it, letting him drop the rest of the way.

“Holy shi- what the _fuck_ \- oh my god! What was that?” Rin gasped out, tears pricking at his eyes as the pain faded away and he could try to figure out what the hell that had just been.

“That was the other reason to keep your tail to yourself, unless you’d like to leave it out?” Amaimon leered at him, clawed fingers pressing against each other as if he was still running them over the fur of Rin’s tail.

A flush overtook Rin as his mind short-circuited and he gaped up at Amaimon, body limp in shock while he processed the last five-seconds.

He was never so thankful for the pain his tail getting yanked on caused him or he would be in an absolutely mortifying situation.

“I’m surprised he didn’t tell you,” Amaimon hummed, dropping the teasing expression he’d been wearing to cock his head at Mephisto, “though I’m even more surprised it took you this long to figure it out.”

Rin came back online, growling up at the demon and twitching his fingers, finding claws had grown there in his anger. “Hey! You couldn’t have just told me? What kinda person just grabs someone like that?”

“But I’m not a person.” Amaimon blinked down at him, though another grin appeared on his face soon after. “And if pain didn’t teach you to keep you tail to yourself, I thought pleasure might.”

“Dammit, keep your claws to yourself!” Rin snarled, his tail thumping against the ground without his say. He reddened when he saw Amaimon watching it with smirking eyes. “I’m putting it away, stop staring!”

Amaimon raised his hands in mock-surrender and Rin sent a long glare at him while he hid his tail under his shirt. It would be aching by the end of the day from being wound up like that, but he’d be damned if he gave Amaimon or any other demon an excuse to grab it again.

“Can we go now?” Rin said, voice pointed as he stood and crossed his arms, fighting the blush on his face until he could look Amaimon in the eyes without it coming back.

“Hmm, I suppose we can, since you don’t seem like you’re in the mood to play with me,” Amaimon teased, ignoring the affronted squawk Rin let out to pick Mephisto back up into his arms.

“So,” Rin said, calmer now when it looked like Amaimon had dropped the topic, “how do we find the next guy?”

“Astaroth,” Amaimon corrected, rolling his eyes and missing the way the name once again made something like anger pinch at Rin’s expression, though he covered it in the next moment.

“And we’re going to follow the coal tars.”

“Coal tars…?”

Rin followed as Amaimon walked away instead of teleporting them, stuck watching the way Mephisto’s hair swayed with every step while Amaimon explained who Astaroth was and why the coal tars would lead them to him.

\---

The voices had left him and, while he’d hated that they’d interrupted his peace when they’d first arrived, he discovered he wanted them back now that they were gone.

Peace, he found, didn’t suit him.

Whoever he was, he was sure of that.

But silence persisted and he cursed that he was so tired, or he would be trying to make his own chaos.

Instead, he was stuck, floating in the gray prison he’d found himself in.

Another ripple.

He held his breath to see what would reach him now.

“It’s a wonder he taught you that much.”

“So, why can’t I keep my tail out?”

Oh? He felt his lips twitch up at the silly question, a gentleman always kept his tail tucked in tight. Didn’t the voice know that?

“What the _fu_ -uh~”

By the moan, he would say the foolish voice had just learned one of the reasons not to leave his tail out.

And by the following shriek of pain, he’d say he just learned the second reason.

“That was the other reason to keep your tail to yourself, unless you’d like to leave it out?”

He liked this first voice, he decided. That response was almost exactly what he would have liked to tell the second voice.

A giggle tried to bubble past his lips, and he realized something.

He felt…

Amused.

But the voices were fading again, everything becoming muffled, and he wanted to scream his frustration, though even the sharp breath that came from his lungs was almost too much effort

He was, once again, trapped in the gray world around him, in the lukewarm waters that he barely felt against his skin and the formless sky that made his vision seem hazy and undefined.

The frustration bit at his bones until the energy it took to feel left him numb and weary so that even that brief respite was gone.

Without those voices, he thought he might go mad in this place.

**Notes for the Chapter:**

> Guys it’s really hard to write these three at ground zero of their relationship again, like what do you mean they haven’t even kissed yet? D:


	3. We're Going to Hell (In a Handbasket)

**Summary for the Chapter:**

> Amaimon and Rin follow the coal tars like a trail of bread-crumbs… Wait, wrong fairytale. Also, that explosion you just heard? That was Rin combusting as he plays the “connect the name to the demon” game. When did Amaimon become the responsible one again?

**Notes for the Chapter:**

> So I’ve got that post update high going for me right now and I figured I’d get while the going was good to start cranking out chapters for BRS while I wait for the new manga chapter coming up for aoex to see if it gives me anything substantial to go off of for Incandescence (I really should have picked an easier fic title to type out, like, how are u supposed to shorten it like BRS???) Asking for a friend bc I keep spelling my own title wrong and then having to correct it (: 
> 
> Also, chapter 110 was lovely (that cover tho, like, Shiemi looked so cool!) but, once again, not what I needed XD What I DO need is to see my gremlin king again. Where’s the green boy, Kato? Produce him!

Amaimon walked ahead of him in silence after he'd explained why the coal tars would lead to Astaroth.

Apparently, as kin of Astaroth, the coal tars were all connected to him in some way that Rin couldn’t sense at all but which Amaimon assured him was obvious to demonic senses, though the unsaid but clearly felt ‘duh’ at the end of his explanation was definitely unnecessary.

They still needed to take the slower route so Amaimon could get a better lock on which of the little demons were more connected since it meant they had been closer to Astaroth recently- or something like that, Rin hadn’t really understood.

Once Amaimon got a general vicinity, they'd teleport there and begin the search again until the location was narrowed down and they found their target. Until then, they were following said coal tars to more of their brethren drifting in the air in mindless patterns.

Watching Mephisto's hair sway with Amaimon's movements was turning into an almost hypnotic effect with nothing else to claim Rin's attention.

He tripped over another root in the ground and decided he'd had enough.

“Uh I can carry Mephisto too, if you want,” Rin hedged.

Amaimon didn’t slow his pace- in fact, he seemed incapable of it, having been going at the same steady speed the whole time.

He did look back at Rin, quirking a brow at the request like Rin had said something weird again.

“No.”

Rin blinked, almost feeling insulted that Amaimon had denied him so simply and without any kind of explanation forthcoming, returning to ignoring Rin.

Okay, Rin narrowed his eyes. He was not going to be doing this whole thing in silence and Amaimon could bite him if that pissed him off.

“Why?”

The question got him a subtle tensing of Amaimon’s shoulders, though Rin couldn’t tell if it was because Amaimon was irritated at it or just Rin breaking the silence again. Or even just having to answer another one of Rin’s questions in general, though he’d seemed fine with answering them before, if a little sarcastic when he answered.

At the very least Amaimon didn’t get angry about them like Bon sometimes did when Rin asked too many things he considered to be obvious.

So it was something else, Rin determined, only to realize Amaimon hadn’t spoken.

“Amaimon?” Rin prodded, hesitant but curious about why he had yet to responded.

“No.”

Rin felt his eye twitch at the stubborn refusal and was about to open his mouth to say something about it- it wasn’t that he wanted to lug Mephisto around like a sack of potatoes, dammit, but it was a matter of principle now!

Amaimon stopped, flicking a clawed finger at one of the floating coal tars near his face and sending it tumbling away through the air before righting itself and carrying on its aimless course.

“I’ve narrowed it down.”

And he raised his fingers to snap before Rin could protest him dodging the question again.

They left the peaceful forest behind.

And entered a concrete hell.

The sounds reached him first, rushing traffic and crowds of people bombarding his senses, unbearably loud after the relative silence they’d just come from. Smells followed close behind, millions of humans and the fumes from passing cars assaulting his nose until Rin had to throw a hand over his mouth to hold back the instinctive gag he wanted to let out.

Once again, besides a wrinkle of his nose, Amaimon seemed unaffected, though he also didn’t look like he enjoyed being around the hordes of people either, if his already blank expression turning stony was any indication.

But Rin was able to adjust to the city after the shock wore off, lowering his hand and taking a closer look to see if he could recognize where he was.

Chaos met his eyes and he blinked once.

Yeah, there was no way he was figuring this one out. Rin inched nearer to Amaimon, who’d been analyzing the new swarms of coal tars, so much more prevalent in the city.

He’d thought Kyoto and even the Academy town had been large, but what he was seeing made them look like quaint villages by comparison.

And, of course, after listening to the voices around him, Rin couldn’t understand a word being said. If he got lost here, he’d be hard pressed to find Amaimon again, or even his way around.

“He’s here.”

Rin jerked his gaze up, startled at the sudden words, “really? That was fast. Uh, where are we?”

Amaimon paused where he’d been about to snap his fingers again, brows scrunching in thought, “I don’t know what the humans are calling it nowadays, or what it would be called in your language.”

“Oh, right,” Rin said. He kept forgetting just how old the demon kings were, that they’d been around for what seemed like most of human history, despite Amaimon looking like he was somewhere in his early twenties.

Mind thoroughly boggled at how truly ancient Amaimon was- and the concept that Rin might one day reach that age, was way too much to think about right then. So, Rin happily put it out of his head and nodded to show he was satisfied with Amaimon’s answer.

It was oddly polite of the demon to even wait for him before teleporting them, Rin had a chance to think, before the snap came and he was blinking his eyes open to a new area.

The same rough buildings and indecipherable language, this time expressed as graffiti fading on the bricks, met him, but there were less people around, the noise of their conversations muffled by the labyrinth of alleys they’d appeared in. He could just hear the hum of human activity but, as they made their way further into the murk, Rin lost even that.

Mysterious stains in the grit of the alley had Rin covering another wince and doing his best to avoid stepping in anything he’d have to smell until it washed off his shoes later.

But there was another scent surrounding him that took his attention away and had him sniffing the air to chase it while he tried to place where he could have smelled it before, coming up blank.

In his distraction he didn’t notice they’d reached the end, though at least this time he didn’t walk straight into Amaimon again, twisting out of the way at the last moment to stumble to a halt at his side instead.

A door, mottled paint flaking to reveal layers of equally worn paint beneath, greeted Rin.

“Er, he’s in here?” Rin asked, already knowing the answer but hoping he was wrong.

“Tch, I don’t know how he stands it either, he always chooses these places,” Amaimon said, an admission Rin hadn’t actually expected from him but made him feel better for the solidarity it provided. He wasn’t the only one uncomfortable, though, as Amaimon was already pushing open the door without hesitation, he definitely covered it better.

It wasn’t as bad once they entered the building. But that wasn’t saying much, Rin grimaced. The lights weren’t flickering, at least, even if they were the type of fluorescent that burned your eyes if you looked too long, and the stench of the city was covered by stale air.

That strange smell was still there, Rin felt his hackles raise.

He jumped as a coal tar drifted past him while he’d been distracted again. In fact, now that he was looking, more of the little demons revealed themselves, filling the claustrophobic corridor until Rin had to brush them aside or have them bumble straight into his face in their nearly aimless journey down side paths he and Amaimon avoided.

Amaimon narrowed his eyes at them, his height not helping matters when it came to keeping out of their path. But he just stalked forwards, head bowed to let the coal tars bounce off his hair and not into his eyes.

Rin followed behind him, not above taking advantage of the clear path he made through the thickening swarm.

Actually, that turned out to only be a temporary solution as the air filled with too many to count and Rin let out an irritated growl, “seriously? What does he need all these guys for anyway?”

Amaimon shook his head and Rin caught a glimpse of gold eyes narrowed in a peeved glare at another coal tar that left a circle of soot on his cheek when it hit him, “it’s better than his mushrooms.”

“Mushrooms?” Rin muttered, trying to figure out why that seemed familiar too. And why it made his claws want to extend.

He tried to think harder about the strange physical reactions that kept piling up without an apparent source that he could remember-

-Then sneezed as a coal tar smacked right into his nose, getting soot inside. Blue flames burst out and incinerated the poor thing in a squeal of its tiny voice and hissing fire.

Noise came from Amaimon while Rin recovered from the surprise attack, realizing it was laughter a moment later and scowling, “hey! I didn’t mean to, it just got in my nose.”

Amaimon shot a smirk back at him, snickering, “you should see your face right now.”

“Yeah, well,” his eyes darted to the similar soot-stain on Amaimon’s cheek, the shape distorted by his grin, “you too.”

Somehow that just made Amaimon smile wider and Rin sensed things were only going to devolve if he let it continue, where, exactly, he wasn’t sure. Though he was sure he didn’t want to find out.

“Isn’t, uh, Astaroth gonna be angry I just killed one of his guys?” He pointed out in an effort to get Amaimon onto a new topic.

Another coal tar hit Rin’s forehead and he batted it away with a swipe of his claws while delight entered Amaimon’s gold eyes at the frustrated move.

Rin glared at him, Amaimon having turned to walk backwards through the swarm so they looked like a dark billowing cloud expanding around his form.

A thought occurred to Rin then as Amaimon opened his mouth to respond, “wait, why aren’t we getting a gift for him too?”

It worked, distracting him from further teasing. Amaimon waved a hand at the question and turned around to continue, “too many gifts will spoil him, I already got him one recently.”

They rounded a corner in the hallway that just kept going, heading towards a slightly ajar door at the end of it that Rin hoped was the location so he could escape the damn coal tars.

And they were through the door.

Rin had a moment to enjoy the wide-open warehouse space that allowed him to breathe without risk of inhaling a coal tar before Amaimon stepped forwards to greet Astaroth.

“Astaroth.”

“Amaimon? is this a personal matter or do you have news for Father?”

That voice.

The scent Rin recognized. He looked around Amaimon's shoulder.

“ _You_.”

Rin saw red.

“My… Prince? Amaimon, what. Did. You. Do.”

The question made Amaimon narrow his eyes, but Rin barely comprehended the sudden wary attention he was being paid.

Because there in front of him was Reiji Shiratori, somehow possessed again, and Rin knew which king Astaroth was and why he was familiar.

“Rin,” Amaimon spoke up, eyebrows scrunched in consternation as he stepped forward, clawed fingers twitching as if he was unsure, caught off guard.

Rin snarled, flames bursting from his mouth. His breath huffed out between extended fangs, the action both open threat and to take in the scent of his target. He vaguely registered that his ears must have lengthened and eyes begun to warp. He couldn’t control it even if he’d wanted to.

Amaimon stopped in his tracks, but his face hardened, a warning Rin didn’t pay any attention.

“Why is he here, Amaimon?” Astaroth made the mistake of speaking.

Everything happened in an instant.

Rin roared his rage, tearing forwards and erupting into flame, his entire intent and focus on reaching the bastard that had led to Shiro’s- to his father’s death.

He’d kill him- he’d _kill_ him!

Only to gag as he was grabbed by the throat and thrown into a wall, thick steel siding screeching as it warped and twisted into the shape of his body from the devastating impact.

Amaimon’s fangs were around his throat halting his shout and the coughed out growls he’d been releasing at having his vengeance interrupted.

He couldn’t move, flames vanishing to leave him in a cold sweat as he felt the needle-point tips press in further, dangerous growl vibrating through them from deep in Amaimon’s chest.

Claws rested at Rin’s middle, ready to gut him if he showed signs of moving in any way that looked like a continued attack.

And he’d dropped Mephisto, Rin realized, eyes prickling with tears in an automatic fear reaction.

A whimper escaped his mouth and he slumped in the hold, giving into the instincts screaming at him to submit to the demon at his jugular.

Seeing he was done, Amaimon gave one more squeeze to his neck before pulling his claws back from Rin’s stomach.

Then Rin was squeaking because a long tongue laved against his throat along the path between fangs as they receded to their normal length and disengaged.

“Amaimon!” Rin gasped out, dropping from the dent he’d made in the wall and rubbing the wet trail before it had a chance to cool on his flushed skin, “What-“

“Why did you attack Astaroth.” Amaimon said, cutting him off before he could yell at him for the massive boundary over-stepping he’d just undergone.

But the question reminded Rin how he’d ended up in the situation in the first place and he couldn’t help the curl of his lip over a fang, gaze darting to Astaroth’s still form, the demon king having taken to watching them in silence as he let Amaimon handle Rin.

Amaimon stepped in front of Rin, blocking his view of Astaroth and releasing his own warning growl until Rin backed down, not wanting a fight.

Rin glanced at Mephisto and he wondered which of the demon kings knew how everything had begun, since Amaimon clearly didn’t.

“He’s the one who started everything,” Rin said voice almost a hiss, bringing his gaze back to meet Amaimon’s, unrepentant, “he attacked my home and my dad’s dead now because he tried to protect me!”

“Tch. That damn interfering exorcist,” Astaroth scoffed and Rin’s heart stopped in his chest at the sheer _god damn nerve_ , eyes widening and body freezing as fury swept through in a blinding red wave-

-Only to crest as Amaimon snarled behind him, “Astaroth. _Stop_.”

Amaimon’s breath left him in an exasperated huff when Astaroth grumbled, crossing his arms but standing down anyway so he could turn back to Rin.

“Astaroth follows our Father and is on Lucifer’s side,” he began when he knew he had Rin’s full attention, “your father would have known that, as he would have known the risks involved in taking care of the son of Satan in the first place- or dealing with Samael at all.”

The way Amaimon said it, laying things out with such cold logic, it hurt. Rin dropped his gaze, chest aching as the entire night came back to him in nightmarish flashes of vivid color while he stood in the cold of the metal warehouse.

“It was an inevitable conflict that he accepted the moment he took charge over you,” Amaimon continued and, Rin was startled to realize, the calm certainty he said it with somehow allowed Rin to breathe deeper and _not_ feel like tearing Astaroth’s throat out with his claws when he caught his scent again.

“I know,” Rin answered when it looked like Amaimon was waiting for a response, voice coming out bitter around grit teeth.

“I know,” he repeated when Amaimon still looked unconvinced, “he was just the first guy who came, and my dad already took care of him before- before…” Rin trailed off, taking a shuddering breath again to force himself the rest of the way calm.

“Good,” Amaimon nodded, un-tensing from the alert stance he’d been in, though he still didn’t drop it completely. They still had to deal with Astaroth.

They returned to where Amaimon had left Mephisto, and Rin didn’t resist the urge to correct the uncomfortable way he’d fallen this time, bending to pull the arm lodged under his body and his legs from their twisted position with careful movements.

The slow process allowed him to steel his nerves further until, brushing the mussed purple bangs from where they’d caught between Mephisto’s slightly parted lips, Rin felt ready to face Astaroth without breathing fire.

He stood, coming to Amaimon’s side where the two demons had been waiting to get down to the real reason they were here.

“Samael is cursed, it’s the King Killer,” Amaimon said without preamble, and Rin settled back to let him talk, not quite trusting himself to speak yet.

The name of the curse prompted a surprised look from Astaroth, his arms tightening in their crossed hold.

“He’s dead already, then, so why did you involve our Prince?” Astaroth said, matter-of-fact and with the same care the rest of the kings had when finding out Mephisto was dying. Rin shouldn’t have been surprised but it hit him with the same disbelief at their callousness as it had when the humans had displayed their own casual cruelty.

Was he the only normal person who cared whether someone lived or died anymore? Rin almost wished Shiemi was there because she was always the only other person who backed him up on these sorts of things. But he would never involve her, or any of his human friends, actually, in something he’d brought on himself, something so dangerous.

They’d probably even protest not being able to help him, Rin suspected, heart hurting because he knew this was something they’d never be able to help him with. This was something only a demon could do.

“He involved himself,” Amaimon said, bringing Rin’s reluctant focus back, “I found them fleeing from Samael’s exorcists. We’ve been to see Beelzebub already for information about the curse. He directed us to you next.”

Each bit of revealed information was stated without wordplay or attempts to cover it up, very different from the way Mephisto liked to tease people with promised knowledge and hints to his true motives.

Rin wondered how much they all spoke amongst themselves, never having considered that Mephisto might be in communication with the other kings, since Amaimon seemed to spend more of his time away from them than together.

“So you've chosen a side, Amaimon.” Rin just contained the jolt those words from Astaroth sent through his body. What did he mean, had Amaimon chosen a side?

“No.”

The short response had Rin hiding a wince, sensing the fault line Astaroth had just stepped on as the same one Beelzebub had skirted around in his encounter too.

“Yet you won't take our prince to Father and you protect Samael, you have chosen a side,” Astaroth continued digging, not satisfied with Amaimon’s negative.

“I. Have. Not,” Amaimon said through clenched teeth, his stance firmly rooted to the ground while Rin considered preparing himself to grab Mephisto and run if the two started fighting.

“Gehenna won't see it that way, _Father_ won't see it that way,” Astaroth kept at it, as if reminding Amaimon where the line in the sand was.

“I know,” Amaimon said instead of explaining himself, gold eyes flashing in warning, saying without words that Astaroth should make up his mind whether he would be helping them or not.

Astaroth watched him with considering eyes and Rin had no idea what his next move would be.

Would they be getting his help and the information he had about the curse, or…

“Then I'll tell you what I know from that time,” Astaroth conceded, closing his eyes and letting the challenge go out of him, the expression on Reiji’s face so out of place Rin was almost able to keep himself from thinking about the arrogant bully he’d dealt with for so much of his childhood.

It seemed so long ago that picking fights with schoolyard bullies had been his greatest obstacle, that and schoolwork in general, though he’d still had to deal with that at the Academy.

He wasn’t sure if he could go back to that simple life, now.

“You'll be facing the consequences of your actions soon, but I'll give you that much,” Astaroth said, his statement a last caution to change course. Which, like hell he’d be listening to whatever Astaroth said, Rin determined, glad to see Amaimon was just as steadfast in his decision.

“I was there, that last week of Abduxuel’s existence, as I’m sure Beelzebub told you already,” at Amaimon’s confirming nod, Astaroth continued, “that overly-excited fool…”

That hadn’t sounded like a compliment, Rin thought, watching how Amaimon twitched at the description of Abduxuel, though he didn’t say anything, letting Astaroth finish.

Astaroth scoffed again, staring into the corner of the warehouse at the coal tars still floating around them, “he was a shell of himself at that point, more dead than alive- well, you’ve felt the pain of degradation to that degree, Amaimon, you’re familiar with the experience.”

The rot, he must mean, Rin hadn’t really seen how bad it could get, but he remembered smelling it on Lucifer and seeing the patches of gray flesh not hidden by his uniform, trying to imagine it covering their whole body, as Astaroth seemed to imply.

It was a horrifying concept and Rin tried to focus on something else other than the memory of decay in the air.

“Samael wouldn’t let anyone in the room with him besides Lucifer at that point, not that we would have wanted to be, with how out of control he was.”

Astaroth chewed at his lips, scowling, a much more familiar expression on Reiji’s face, “and of course, not that any of that matters to you, since you decided to fuck off around Assiah back then.”

Amaimon growled, teeth clacking together in sharp irritation, “that’s not what I need to know, Astaroth, is there a cure to the curse.”

“Typical, Amaimon,” Astaroth snorted, “but yes, there is something you wouldn’t know that might be useful.”

“Well?” Came the impatient prompt.

“Abduxuel wasn’t the first of us to be afflicted by this curse.”

Rin sucked in a breath, that was it. That was the information they needed. The chances that another had been cursed and even survived going up even further.

But Amaimon didn’t react to that information and Rin wondered if he’d already thought of that possibility.

“But only Lucifer knows who it was,” Astaroth added, crushing the hope that had been budding, sending them back to square one because the answers still all seemed to point to Lucifer and, as Rin had been repeatedly told, they couldn’t go to him without signing his death warrant.

“Could it have been Azazel?” Amaimon asked, focus inward as he tapped a claw to his bottom lip, scratching lightly until it bled and he blinked back into awareness, “he was always strange, he could have been afflicted.”

“Yes, Azazel is a weird one,” Astaroth agreed, and Rin wondered what could have been so odd about who he was presuming was another of the kings that could have someone like Amaimon calling him strange. “But I don’t think so, at least, he never indicated that he might have, and he seemed just as… bothered by Abduxuel’s state as the rest of us were.”

“So, what would you suggest, then,” Amaimon brought them away from the topic of Azazel’s weirdness, waving a hand to brush it aside.

Astaroth shifted, uncrossing his arms to place his hands on his hips, the move so reminiscent of Reiji that Rin felt another pang of guilt, even though he’d been such a bastard of a human.

What had the human Amaimon inhabited been like? Was he still in there, like Izumo’s mom had been, in the end? It wasn’t a pretty thought and Rin buried it for another time.

“Iblis,” Astaroth finally said, dropping his arms, though Rin had no idea what or who an Iblis was, “she is closer to Lucifer, for a given sense of the word, though not as close as Egyn, and he may have told her what he didn’t tell me ”

“That’s too close,” Amaimon said at the mention of whoever Egyn was, “Egyn stays at Lucifer’s side, we can’t approach them.”

At that, Astaroth smirked, “and there’s the fact that you never much liked them, if I recall.”

Amaimon glared and the reaction had Rin blinking. What kind of demon could Egyn be that Amaimon wouldn’t get along with them? He seemed so laid back all the time, what did it take to make him dislike someone enough to go out of his way to avoid them.

He’d probably be waiting for a while longer to learn about that relationship, Rin figured, knowing Amaimon wouldn’t bring it up on his own and might be annoyed if Rin did.

Although, Rin might get Amaimon to tell him about Egyn and Iblis at the same time if he phrased the question the way he had about Beelzebub and Astaroth. As something to know about demon politics and how they fit into the scheme of things. That way Amaimon wouldn’t think it was a personal question and was just another thing to educate Rin on so they’d have a better chance of surviving this!

Despite himself, Rin found he had to fight to keep a smile from his face, the thought of, not manipulating, but learning more about Amaimon in such a clever way filling him with a giddiness he couldn’t quite explain the source of.

A sigh came from Amaimon and Rin realized they were done.

“Thank you, Astaroth,” Amaimon said without inflection, more formality than anything as he walked to Rin’s side to bring Mephisto back over his shoulder.

“Your time will run out faster than you think, Amaimon,” Astaroth warned, the gravity of it making Amaimon still, body hunched and face shadowed by his choppy green hair from Rin’s sight.

“I know, Astaroth.”

And Amaimon rose the rest of the way, flicking his hand at the door to indicate Rin follow as he stalked past.

Well, Rin wouldn’t be thinking twice about that, anything to get out of the uncomfortable presence and away from the scent of rot and coal dust filling the room.

And away from Astaroth- although, Rin stopped, hands fisting as he turned to Astaroth.

“Before we go,” Rin stared into those familiar red eyes, now completely changed from the boy he once knew, “how did you posses Reiji again. My old man said he sealed him against possession.”

Astaroth leveled a steady gaze back at him from slit-pupils, “those are not impossible to overcome, my Prince, provided you have another demon or exorcist who can remove it from the body.”

Rin nodded, accepting that and trying not to let the hate rise in his gut again for the answer he had suspected, “thanks.”

And left with Amaimon without a backwards glance.

* * *

 

 The voices had left with his awareness an indeterminate time ago and hadn’t returned with his waking- if what he experienced could be considered waking at all.

If he could have sobbed, he would have.

Had he ever cried before? The act seemed unfamiliar to his mind as well as his body.

But he was sure he wanted to now. He wanted to be able to do _anything_ now.

A sharp exhale left his mouth, chest squeezing with the effort as his vision blurred in exhaustion and agony.

The pool of water that made up his entire world rippled.

Another gasp, this time one that would be a sob of relief were he capable of it.

They were _back_. Please let them be back.

“He’s the one who started _everything!_ ” The second voice shouted, raw anger and emotion sending his pulse skipping a beat in his chest as he wondered who ‘he’ was and what he’d started.

He latched onto every word, savoring them like they would be his last and greedy- desperate, for more.

“He attacked my home and my dad’s dead now because he tried to protect me!”

Was it his imagination or was the voice louder, more real than it had been when he’d heard it last?

And what did that mean if it was?

“Tch. That damn interfering exorcist,” a familiar voice, a third one that he couldn’t place a name to.

But the word exorcist made another twinge of familiarity go through his heart.

“--------. _Stop_.”

The first voice again, struggling to calm the second and third voices down, he could hear.

“-------- follows our Father and is on -------‘s side.” There were names missing, he could hear where they would be. _Why_? Why were they missing? Who were they and _why was this happening to him_?

“Your father would have known that, as he would have known the risks involved in taking care of the son of ----- in the first place.”

The urge to scream his frustration was back again.

“It was an inevitable conflict that he accepted the moment he took charge over you,” the first voice continued, not letting go of the cool logic that he admired the more he heard it.

Emotions were ugly little things that could be manipulated so easily, but…

…But they were all he had in this cruel place he’d found himself in.

“I know,” the second voice answered, a bitterness that seemed to reflect the strange melancholy filling him at the topic of their conversation.

There was something about this exorcist- this father the voices spoke of, that had dulled tendrils of melancholy- or possibly regret, coiling through his chest that he couldn’t explain any more than he could explain why everything they said made him feel as if he should be intimately aware of who the exorcist was and the part he played.

“I know,” the second voice repeated, and he could hear the fight go out of him.

“He was just the first guy who came, and my dad already took care of him before- before…” the voice trailed off, a final concession to the wisdom of the first voice.

“Good…”

He was fading again, teeth closing together, though he didn’t have the strength to clench them in the frustration he felt but lacked the energy to express.

But he’d lasted longer this time, heard _more_.

Was he getting stronger? Could he escape this place on his own, given enough time and effort?

The thought gave him hope that followed him down in a tangled mix between frustration and still lingering melancholy.

* * *

 

 The last door shut behind them and they were back in the outside world between the walls of the alley.

“We don’t have to worry about him like Beelzebub?” Rin asked when he thought they were far enough away and he noticed Amaimon hadn’t teleported them like he had before.

Amaimon shook his head, focus on something else, probably the politics that Rin was beginning to see played a large part in every interaction between the demon kings. It was… kinda exhausting, and Rin realized why Amaimon seemed to avoid the others whenever he could now.

Well, with the exception of Mephisto. Rin glanced at him, watching the way his face looked slackened in sleep. Did it have less color in it than this morning? He couldn’t be sure, the already dim surroundings in the shadow of the alley muting his features.

“Astaroth is straightforward in his allegiances,” Amaimon said, startling Rin again as he leant back against the alley wall with the shoulder opposite the one he carried Mephisto on.

“So that’s good?” Rin needled, trying his best to understand the personal versus political relationships between the kings.

“He’ll do as he said he would,” Amaimon said, shrugging, though he didn’t look especially happy about that and Rin wanted to pull his hair out because he still didn’t know if that was good for them or not. “He’ll report this to Lucifer.”

Rin sighed, giving into the urge to scratch at his arms before forcing himself to stop the frustrated habit, “Lucifer. Who you and Beelzebub said we _shouldn’t_ go to because he might take me straight to Satan?”

He got a slow blink from Amaimon and a nod in confirmation, though it seemed to be humoring him and not because he was being particularly helpful.

“I don’t get it.” Was he whining? Yes. Yes, he was. By the twitch of Amaimon’s lips upwards Rin could tell he heard it and was definitely laughing at him inside. Bastard.

Rin scowled, crossing his arms and raising a brow, “well, what now?”

That brought out the smirk Rin had known Amaimon was hiding.

“Now, we go to Gehenna. We have no other choice, as you heard from Astaroth, Iblis, King of Fire, is our next target.”

Gehenna. Rin had known it was coming down to that place- that world of demons, ever since it had been brought up by Amaimon.

What would a world like that even be like? Somehow, after seeing the demon kings and even minor familiars like Kuro, Rin had a hard time believing it was anything like the religious books he’d been forced to go through at the church as a child.

He’d be finding out soon, whether he was ready or not.

His gaze wandered the alley until, with nothing but the dirty brick to take his attention, he focused on the contemplative figure of Amaimon- and Mephisto.

“His suit’s covered in soot still,” Rin finally said after shaking himself from his thoughts, “he’d be really pissed it was dirty, he was always telling me to clean up or dress nicer, you know? And then he’d do that snapping thing you guys do and fix my hair and clothes anyway.”

Amaimon stared at him with those unblinking eyes again, as if he’d seen something that surprised him or had made him re-evaluate what he’d known. Like a puzzle he’d found new pieces for- or had revealed itself to be of an entirely new picture than the one he’d been building.

Rin shuffled at the intense stare, though he kept his gaze steady because he refused to show weakness. It was more important than ever to keep himself true to his human ways, even if he would have to start learning what it meant to be a demon.

“Living as a human must be incredibly,” Amaimon searched for the word while Rin startled at the sudden break in their staring contest, “tedious.”

He snapped his fingers and Mephisto’s suit was back to its spotless white. For some reason that made Rin feel better about what he was about to do. About going to Gehenna.

“Okay,” Rin breathed, it was okay, now, right? He began to walk a few steps, turning to walk the other way when he realized his steps were purposeless.

“There’s something else,” Amaimon said, abrupt and halting Rin from his pacing.

“What?” Rin asked, wary as something off in Amaimon’s usually laid-back tone sent warning bells ringing in his head.

“When you go to Gehenna, the flame that's trapped in your sword will come back in full to your body if it's unsheathed. You'll more than likely die if that happens. You can't draw it.”

Amaimon could have punched him into a wall again and it would have had less impact than those words did.

He couldn’t breathe, staring into cool gold eyes as he tried desperately to process the thought of being even more defenseless than he already was.

“What?” He managed to ask, hoping for clarification of any kind.

“The sword- it’s a gateway to Gehenna where the majority of your flames, your demonic heart, reside,” Amaimon tilted his head, “did Samael really not tell you any of this?”

Rin flushed, for some reason feeling shame at not knowing something he shouldn’t have been expected to know in the first place, all because it was a demon thing, “no, I don’t think he told me much of anything, now.”

Amaimon furrowed his brows, shooting a look at Mephisto. It somehow carried more than the simple irritation he’d held the first time Rin had told him how much of his heritage Mephisto had kept in the dark.

“I need to call Yukio,” Rin said, the words coming to him from numbed lips while his hands fumbled the burner phone he’d been given just that morning, already feeling like it had been longer- a different world than the one he was in now.

That got another tilt of Amaimon’s head at him, though he was only aware of the curious gaze on the periphery of his mind, typing in his twin’s number and hoping he picked up.

It rang.

And rang.

And rang.

The message tone played and Rin took a shuddering breath, leaning back against the wall to hold himself up as he tried to think of what he could possibly say.

“Yukio,” he started with no other ideas forthcoming, “I’m going to Gehenna, Yukio. We have to track down more information and there’s no one left on Assiah to get it from so…”

“…So I-“ Rin scratched the claws of his hand not holding the phone into the wall behind him, the sensation of gouging brick helping him gather himself.

He knew what he had to say. The only thing that really mattered, in the end.

“Yukio, tell Shiemi and Shura- and Bon, Konekomaru and even Shima- and everyone from home, and Kuro," Rin let out a self-deprecating laugh, realizing he'd made more friends than he'd thought. And that he'd possibly be leaving them behind forever.

He turned his eyes down, hand clenching on the phone before he forced a shivered exhale out and continued, "tell them I'm-"

The phone beeped again, message ending and cutting him off, "-sorry."

Rin stared at the screen for a few moments longer, hoping Yukio got his message and that it was enough. He pocketed the phone and nodded to a, once more, shockingly patient Amaimon.

He was ready.

But Amaimon didn’t just take them straight to Gehenna, how ever that worked, anyway.

Instead he pushed off from the wall to stride down the alley, forcing Rin to follow behind him as confusion about their destination bubbled in his mind.

“Why are you sorry.”

The words shocked Rin and he stumbled, staring up at Amaimon where the demon continued to walk as if his question hadn’t thrown Rin for the biggest loop.

“What?”

Amaimon stopped and sent him a narrowed eyed glance before clarifying, “just now, to your twin, why were you sorry when you already explained to him why you’re doing this earlier, and he’s likely already told those others you mentioned about it, too.”

That, Rin couldn’t take his wide-eyed gaze off Amaimon, he didn’t know what to do with that question.

The look on Amaimon’s face started to turn irate and Rin quickly remembered he didn’t like being made fun of or ignored, opening his mouth to say the first thing he could think of.

“Because I’m leaving them and I might never see them again- and they might never see me again,” Rin said, realizing the absurdity of explaining something so simple yet, now that he’d thought about it, so utterly human to the demon king of earth, stunned that he was even curious about it in the first place.

“It’s so they have something from me, even after I’m gone and that they know I thought about them, and I’m thinking about them, and I haven’t forgotten them.”

Amaimon shifted, silent again, and Rin wondered whether he should try explaining further, though he wasn’t sure what to say anymore.

“I still don’t understand,” Amaimon spoke up, hand tightening on Mephisto’s back, “there was no other choice, your actions were the only options with the most optimal outcome you could have taken with the information you had.”

“That’s-” Rin paused, struck speechless. The only option? Best possible outcome? Did Amaimon really think that? He, Rin had thought he’d screwed up yet again, Yukio’s anger before he’d left him telling, because his twin was always the more logical and strategic of the two, right?

His mouth worked without words as he tried to process those questions, prompting Amaimon to sigh and chew at one of his long black claws, “Samael is the only one who kept you safe in Assiah. If he had fallen and you didn’t try to save him, you would be signing your own death warrant because Lucifer wouldn’t wait long to come after you for our Father.”

Ice cut through Rin’s spine like a cruel dagger and he shivered despite his natural core of fire and the warm weather.

“Oh,” he whispered, eyes darting down, “I hadn’t really thought of that- I remember you and Beelzebub said something like that earlier, about Lucifer and his deals with Mephisto.”

“Yes,” Amaimon’s simple agreement had Rin sucking in a breath, steadying himself, “so I don’t see why you need to apologize.”

He was right, in his own way, Rin sniffed as his nose prickled with his rising emotions, chasing the last of his regrets away before they manifested and saw the sound made Amaimon’s eyes narrow, like it bothered him somehow.

It made Rin smile, feeling lighter than he had since the entire start of the catastrophe that he’d found himself in, “you’re right, thanks, Amaimon.”

“Hn,” Amaimon grunted, head jerking to the side as if to avoid Rin’s smile, “are you done with your human business?”

“Yep,” Rin beamed wider. His situation might suck, and he might die in the process or even fail at saving Mephisto entirely. But he was ready to try.

“Let’s go to Gehenna!”

A snap-

Sounds, like the world itself was screaming directly into his ears, loud enough to make Rin cry out in both shock and pain as his vision blurred and his awareness fell with it.

The last thing he saw was Amaimon staring down at Mephisto, expression unreadable and nose a scant inch away from the body he held, as if he was about to press it the rest of the distance into the white folds of fabric there.

Rin’s conscious slipped from him as the earth tilted beneath his feet.

* * *

 

“I’m-“

The message cut off, room echoing with the beep of the tone.

Yukio watched his phone screen go black with inactivity, Rin’s words and the information revealed in them burning in his mind.

“There you have it, Sirs, the spawn of Satan is going to Gehenna.”

Yukio quelled his reaction to the confirmation of his thoughts from the Arc Knight on the other side of the table while he spoke with the Grigori through the video screen.

“Well, that’s a real kicker, eh, kid?”

Yukio didn’t hide the glare at being referred to so insultingly by the Arc Knight.

“What will you do with this information, then, Sir Lewin?”

A wide, carefree smile lit up the Lightning Knight’s face, Yukio’s cool irritation somehow delighting him rather than bothering him.

Nothing seemed to bother him, not even their possible annihilation at the hands of Satan when he gained control of Rin’s body and opened a Gehenna Gate between Assiah and Gehenna.

Rin…

God. _Fucking_. Dammit, Rin.

He was going to _lose_ him.

He was already lost the moment he saved the demon king of time.

Shiro- _dad_ , Yukio caught himself thinking the name and shoved the urge to cry down deep where it couldn’t hurt him. Father Fujimoto wasn’t there to fix things, wasn’t there with a steady hand and laid-back grin on his face to chase the demons away anymore.

Yukio had to handle this himself now.

“Well,” Lewin scratched at his unwashed ratty hair with dirt-stained nails, smile still on his face, “we gotta prepare for war with Satan, obviously.”

War, Yukio gulped, closing his eyes and dropping his chin to his chest.

They were going to war.

**Notes for the Chapter:**

> So I guess Amaimon is really just out there, taking Rin on a “romantic” tour of Assiah and Gehenna, like, when will your fav ever XD They’re missing out on the romantic candlelit dinners though, Amaimon’s gotta get on that, since Rin is gonna be hard pressed to cook on the run lololol
> 
> I’m not sure if tracking works like this in the series either. Like, Lucifer seems to be able to sense when Amaimon possesses a new body in Assiah, but do they know where the other kings are at all times? 
> 
> Or just that they’re in whichever dimension they’re currently in (i.e. bc Lucifer was in Assiah, he could sense that Amaimon appeared in Assiah too, but didn’t seem to know he’d left his old body and gone to Gehenna earlier), or just that they’ve gained a new body, but can’t feel whether they’ve jumped between worlds or which world they’re in? 
> 
> Idk but for this fic’s purposes I’ve gone with that they can sense when another king has entered/possessed a new host, but not that they’ve jumped dimensions or what world they’re in.
> 
> (Once again, I am no longer surprised at myself for 22 pages, just begging for the sweet release of death bc it's 3 am and what even is a real sleep schedule anyways? Jk, guys, jk ;D).


End file.
